To get this achievement, you only need to let the time pass doing other quests.
As soon you're done with the intro on your new Ranger HQ and are free to take the Kodiak to world map or go to Downtown Colorado Springs. Make a save and go to world map to receive 2 calls, one right after leaving the HQ and the second a little further down the path. Now, go back to Colorado Springs and keep doing the quests in the region, the ones i did was Top Doc, Cornered Rats, then just talked to Gideon Reyes to get progress on Unwelcome Guests, and then finished Big Trouble in Little Vegas. As soon you finish the last one, go to the map and you will receive a call that some BAMFS got in the HQ, and right after this, another two calls, one of each place you should had saved.
Just Remember that there are two other achievements related to save each place (that's why you should make that save).
And if you go for Hoon Hero, you can get as well this one too...